This is a nationalization of PCT/FR00/00951 filed Apr. 13, 2000 and published in French.
The present invention relates to a disposable so-called safety syringe.
Disposable syringes that must be discarded after use have been developed to prevent contamination: such syringes generally includes a pump body attached to the needle protected by a sheath before use. However, it has been realized that it is possible to refill these syringes and therefore to reuse them, whence serious risks of contamination.
One example of a disposable hypodermic syringe is described in U.S. Pat. No. 5,045,064. The syringe described includes valve means consisting of a stud mobile along a threaded shaft, a diaphragm between the stud and the needle. During an injection, the liquid to be injected, pushed by the plunger, entrains the stud by rotation along the diaphragm which traps it but allows the liquid to pass through it.
The syringe can therefore be used again if the stud does not cooperate with the diaphragm.
So, one aim of the present invention is to provide a disposable so-called safety syringe that cannot be refilled after it is first used.
Another object of the invention is to provide a syringe of this kind which can be manufactured easily and at lower additional cost compared to existing disposable syringes.
The above objects, and others that will become apparent hereinafter, are achieved by a disposable so-called safety syringe including a cylindrical pump body which is extended by a needle fastened to the body and which includes a plunger and a distal part fitted with the needle and a proximal part of larger diameter including a the plunger, the distal part including valve means, characterized in that the valve means comprise, on the one hand, a fixed member fastened to the inside wall of the distal part and a mobile member between the fixed member and the outlet from the proximal part into the distal part, the mobile member consisting of a valve connected by a compression leaf spring one end of which is fastened to the base of the valve and the other end of which is fastened to the inside wall of the distal part of the pump body.
The fixed member advantageously consists of at least one abutment fastened to the inside wall of the distal part of the pump body.
In a preferred embodiment of the invention the fixed member includes at least two abutments regularly distributed on a common circle and fastened to the inside wall of the distal part.
The valve is advantageously of cylindrical-conical shape, the conical part being directed towards the proximal part of the pump body and the cylindrical part including the propulsion means such as fins disposed at its periphery.